The main direction of the project is immunological involving complement interaction with immune systems as part of a continuing interest in the autoimmune diseases and the role of serum complement. The ultrastructural applications include the electron microscope studies of human complement components and their molecular interaction with each other and immunoglobulins. The first project concentrates on the ultrastructure of Clq and its interaction with immunoglobulins. Project (2) involves a morphological study of Bordetella pertussis including localization of biologic activities (especially lymphocyte and histamine sensitizing activities) to one of two structural entities present in the bacterial cell wall and liquid culture (supernatants). This collaborative study with Dr. S.I. Morse (Downstate Medical Center) has already achieved separation of these two ultrastructural particles by cesium chloride centrifugation. Immunochemical and further biological correlations are planned with each of the isolated particles and specific antisera prepared against them. The lymphocytosis promoting factor (LPF has been found to be mitogenic for T lymphocytes in mice and is also mitogenic for human peripheral blood lymphocytes. Project (3) is concerned with the immunosuppressive properties of human chorionic gonadotropin (hHCG). In collaboration with Dr. Robert Canfield, crude hHCG was found to be more immunosuppressive than pure hHCG. Another study includes the purification and characterization of an immunosuppressive peptide from plasma.